SEATTLE, WA, Dec. 19, 2012 /PRNewswire/ - Oncothyreon Inc. (Nasdaq: ONTY) today
announced that the pivotal Phase 3 clinical trial of L-BLP25 (formerly
referred to as Stimuvax®) known as START did not meet its primary endpoint of an improvement in
overall survival in patients with unresectable, locally advanced stage
IIIA or stage IIIB non-small cell lung cancer (NSCLC). The trial was
conducted by Merck Serono, a division of Merck KGaA of Darmstadt,
Germany, under a license agreement with Oncothyreon.

Despite not meeting the primary endpoint, notable treatment effects were
seen for L-BLP25 in certain subgroups. Further analyses are planned in
the coming weeks to explore the potential benefit-risk profile of
L-BLP25 in certain populations. Merck Serono will discuss these data
with external experts and regulatory authorities over the coming
months. More detailed results from the START trial will be submitted
for publication in a peer reviewed journal and presentation at upcoming
scientific meetings.

"We believe that the START study will offer important scientific
insights to the potential for immunotherapies in the treatment of this
devastating disease and we intend to discuss these data with scientific
community and regulatory authorities to gain their advice on potential
next steps," said Dr. Annalisa Jenkins, Head of Global Drug Development
and Medical for Merck Serono. The ongoing clinical program of L-BLP25
that includes studies in the Asia Pacific region will continue pending
discussion with relevant regulatory agencies.

START was a randomized, multicenter, double-blind, placebo-controlled
trial that assessed the efficacy, safety and tolerability of L-BLP25 in
patients with unresectable stage III NSCLC who achieved a response or
stable disease after chemoradiotherapy. Patients were randomized to
receive either a single low dose of cyclophosphamide followed by
L-BLP25 (weekly injections for eight weeks followed by injections every
six-weeks until progression) plus best supportive care (BSC) or placebo
plus BSC. More than 1,500 patients from 33 countries were recruited
into the START trial.

Patient safety in the START trial was monitored frequently by an
independent data monitoring committee and no new or unexpected safety
concerns were noted for the study. In prior clinical studies, the most
frequently reported adverse events included injection site reactions,
flu-like symptoms, nausea, cough, fatigue, and dyspnea.

"These results from the START trial are disappointing, both for patients
with NSCLC and for the many who have been involved in the L-BLP25
program," said Robert L. Kirkman, M.D., President and CEO of
Oncothyreon. "L-BLP25 has been under development for more than a
decade at Oncothyreon and its predecessor company, Biomira Inc. of
Edmonton, Alberta, in collaboration with Merck KGaA. The contributions
of many employees at each company, committed investigators and,
particularly, the many patients who participated in multiple clinical
trials over many years are gratefully acknowledged."

Conference Call and Webcast

Oncothyreon will conduct a conference call today, December 19, 2012 at
8:30 a.m. Eastern time (5:30 a.m. Pacific time) to discuss the outcome
of the START trial and provide a review of its pipeline of products in
development. To participate in the call by telephone, please dial
(877) 280-7291 (United States) or (707) 287-9361 (International). In
addition, the call will be webcast live and can be accessed on the
"Events" page of the "News & Events" section of Oncothyreon's website
at www.oncothyreon.com. An archive of the webcast will be available after completion of the
discussion and will be posted on Oncothyreon's website.

About L-BLP25

L-BLP25 is an investigational MUC1 antigen-specific cancer immunotherapy
that is designed to stimulate the body's immune system to identify and
target cells expressing the cell surface glycoprotein MUC1. MUC1 is
expressed in many cancers, such as non-small cell lung cancer (NSCLC),
and has multiple roles in promoting tumor growth and survival. L-BLP25
was being investigated in the Phase III START trial and is currently
being investigated in the INSPIRE trial, both for the treatment of
unresectable stage III NSCLC.

Merck obtained the exclusive worldwide rights for development and
commercialization of L-BLP25 from Oncothyreon Inc., Seattle,
Washington, USA, in 2007, in an agreement replacing prior collaboration
and supply agreements originally entered in 2001. In Japan, Merck
entered into a co-development and co-marketing agreement for L-BLP25
with Ono Pharmaceutical Co., Ltd., Osaka, Japan.

The START study was a Phase III, multi-center, randomized, double-blind,
placebo-controlled clinical trial designed to evaluate the efficacy,
safety and tolerability of L-BLP25 in patients suffering from
unresectable, stage IIIA or IIIB NSCLC who have had a response or
stable disease after at least two cycles of platinum-based
chemoradiotherapy. The study involves more than 1,500 patients in 33
countries. The primary endpoint of the START study is overall survival.

The INSPIRE study is a Phase III, multi-center, randomized,
double-blind, placebo-controlled clinical trial designed to evaluate
the efficacy, safety and tolerability of L-BLP25 in patients of Asian
heritage suffering from unresectable, stage IIIA or IIIB NSCLC who have
had a response or stable disease after at least two cycles of
platinum-based chemoradiotherapy. The design of the INSPIRE study is
almost identical to the START study. INSPIRE will enroll approximately
420 unresectable, stage III NSCLC patients across China, Hong Kong,
Korea, Singapore and Taiwan.

About Oncothyreon

Oncothyreon is a biotechnology company specializing in the development
of innovative therapeutic products for the treatment of cancer.
Oncothyreon's goal is to develop and commercialize novel synthetic
vaccines and targeted small molecules that have the potential to
improve the lives and outcomes of cancer patients. For more
information, visit www.oncothyreon.com.

Forward Looking Statements

In order to provide Oncothyreon's investors with an understanding of its
current intentions and future prospects, this release contains
statements that are forward looking, including statements related to
analysis and development of additional insights from clinical trial
results, as well as statements related to the timing, duration and
results of clinical trials. These forward-looking statements represent
Oncothyreon's intentions, plans, expectations and beliefs and are based
on its management's experience and assessment of historical and future
trends and the application of key assumptions relating to future events
and circumstances.

Forward-looking statements involve risks and uncertainties, including
risks and uncertainties related to potential insights from the START
study, potential treatment effects of L-BLP25, the safety and efficacy
of our product candidates and the timing, duration and results of
clinical trials, as well as risks and uncertainties related to
Oncothyreon's business and the general economic environment. Many of
these risks and uncertainties are beyond Oncothyreon's control. These
risks, uncertainties and other factors could cause our actual results
to differ materially from those projected in forward-looking
statements. There can be no guarantee that the results of preclinical
studies or clinical trials will be predictive of either safety or
efficacy in future clinical trials. These and other risks and
uncertainties are described in the reports and other documents filed by
Oncothyreon Inc. with the SEC and/or Canadian regulatory authorities.

Although Oncothyreon believes that any forward-looking statements
contained herein are reasonable, it can give no assurance that its
expectations are correct. All forward-looking statements are expressly
qualified in their entirety by this cautionary statement. For a
detailed description of the risks and uncertainties associated with
Oncothyreon, you are encouraged to review the official corporate
documents filed with the securities regulators in the United States on
U.S. EDGAR and in Canada on SEDAR. Oncothyreon is under no obligation
to (and expressly disclaims any such obligation to) update or alter its
forward-looking statements whether as a result of new information,
future events, or otherwise.